Mike---I didn't receive your original request for information on the
"Ignitor," (nor much of anything lately from the list.)
However, if the main concern about improved performance or fuel economy
is where your interest lies, there are some general guidelines that I
feel are key to any new igition system.
If the new ignition uses a separate electrical power source to fire (the
plugs) then it can be set up to throw a more powerful spark, a spark of
longer duration, or both. Both of these will allow firing of a leaner
mixture without misfiring, or a richer mixture without misfiring. This
will be determined when the fuel/air mix is being dialed in. The type of
spark that fires it will have more lattitude if it has a more powerful
unit to work with.
The stock point system is adequate when the rest of the engine does not
require a spark plug that can "fire under water," so to speak.
Electronic ignitions will keep the plugs cleaner and the point life
longer by putting out a stronger spark to the plugs,
(enough to run "cold" plugs if need-be) and transference of metal from
point to point is kept at a minimum with the negligible arcing from
these modern units.
They are only cost effective if the owner plans to keep his car for many
years, or must have a spark supply to compliment the other performance
modifications done to the engine. These modifications would include a
very high compression ratio, a camshaft of long duration, and
carburation that fouls out sparkplugs quickly under "street" conditions.
On the subject of wear in the distributor shaft, which could potentially
cause the point gap to vary slightly; I would think that this would be
spotted when using a dwell meter, if the "wobble" were great enough. To
my way of analysing, if the dwell angle doesn't change thruout the rpm
range, the points aren't floating. This can be backed up with the info
from the timing light. If it stays reasonably steady, there isn't a
problem to be dealt with.
All told, I'm not one who thinks everything on a TR should stay as the
factory built it. But if the changes made to stock don't pay back the
right dividends, I'm inclined to advise owners to leave well enough
alone.
No one has yet said what these optical or magnetic units have done to
improve their TR. I would like to hear from some of them...
DickTaylor
'73, with MSD
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